首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3199篇
  国内免费   72篇
  完全免费   605篇
  神经病学   3876篇
  2019年   29篇
  2018年   186篇
  2017年   222篇
  2016年   198篇
  2015年   154篇
  2014年   228篇
  2013年   190篇
  2012年   239篇
  2011年   320篇
  2010年   228篇
  2009年   309篇
  2008年   275篇
  2007年   234篇
  2006年   132篇
  2005年   108篇
  2004年   93篇
  2003年   98篇
  2002年   88篇
  2001年   69篇
  2000年   2篇
  1999年   45篇
  1998年   46篇
  1997年   49篇
  1996年   49篇
  1995年   59篇
  1994年   49篇
  1993年   37篇
  1992年   29篇
  1991年   21篇
  1990年   27篇
  1989年   25篇
  1988年   19篇
  1987年   13篇
  1986年   4篇
  1985年   2篇
排序方式: 共有3876条查询结果,搜索用时 46 毫秒
1.
目的研究功能区胶质瘤术中完善而有效的锥体束空间定位和功能保护方法。方法对13例功能区胶质瘤应用1.5T磁共振系统采集弥散张量成像(DTI)数据,在功能神经导航中进行纤维束示踪(FT),在导航中确定肿瘤与锥体束界面的标记点,应用自制导航穿刺针、着色明胶海绵对白质内锥体束走行进行空间定位。在空间定位锥体束基础上,应用皮质、皮质下直接电刺激或唤醒麻醉技术在肿瘤切除中对锥体束功能进行评估监测,保证其正常功能。结果本组锥体束与肿瘤交界区在神经导航中均得到确定,术中在DTI-FT导航下空间定位满意;锥体束功能判定明确者10例。均全切肿瘤,运动功能保持术前正常水平或得到改善。结论联合应用DTI-FT导航、神经电生理或唤醒麻醉技术可确保锥体束功能不出现手术损伤,同时为明确胶质瘤在脑白质内功能性边界提供有效方法。  相似文献
2.
Summary: Cortical dysplastic lesions (CDLs) are usually identified by magnetic resonance imaging (MRI). Clinical, electrographic and histologic findings suggest that focal CDLs (FCDLs) are highly epileptogenic, often involve the rolandic cortex, and can present variable degrees of histopathologic abnormalities. An ictal or "ictal-like" bursting pattern of electrographic activity was recorded over dysplastic cortex in 65% of our patients. Resective surgery can eliminate or significantly reduce seizure frequency in many medically intractable patients, depending on lesion location, degree, and extent of histopathologic abnormalities. Best results are achieved when complete or major excision of both the MRI-visible lesion and the cortical areas displaying ictal electrographic activity can be performed. This is more likely when the degree of histopathologic abnormality is mild to moderate or when the lesion is in a temporal lobe. More severe histopathologic abnormalities and central insular or multilobar lesions usually lead to less favorable results: either major excision of the visualized lesion is impractical or the lesion is microscopically more extensive than shown by MRI. Multilobar resection or hemispherectomy for patients with infantile spasms associated with CDLs and for patients with hemimegalencephaly are often associated with dramatic improvement in seizure control. Callosot-omy can be performed in selected patients with diffuse CDLs who have intractable drop attacks.  相似文献
3.
MRI-Based Hippocampal Volume Measurements in Epilepsy   总被引:14,自引:14,他引:6  
4.
We report transient changes in computed tomography (CT) and magnetic resonance imaging (MRI) scans in a patient with focal status epilepticus, referred to us with a tentative diagnosis of neoplasm based on CT and angiographic findings. EEG seizures originated independently from each temporal-occipital area, predominantly from the right. Previous EEGs had shown almost exclusively right temporo-occipital epileptogenic activity. MRI showed increased signal intensity, and CT showed decreased right hemisphere attenuation without enhancement. One month later, there was resolution of the radiological and clinical abnormalities. The transient CT and MRI changes probably represented focal cerebral edema, developing during focal status epilepticus. Lack of change in the left hemisphere probably reflected the quantitative difference in epileptic activity. Clues to the diagnosis of focal edema due to status include: (1) changes on electrical and imaging studies that correlate anatomically with the clinical status, and (2) resolution of abnormalities with appropriate seizure control. In patients with suspected seizure disorders, electrical and clinical data should be correlated before interpretation is made of focal lesions seen by neuroimaging techniques.  相似文献
5.
Cortical and Hippocampal Volume Deficits in Temporal Lobe Epilepsy   总被引:13,自引:13,他引:9  
Summary: Purpose : To use quantitative magnetic resonance imaging (MRI) methods to examine the extent of volume abnormalities in the hippocampus and in extrahippocampal brain regions in localization-related epilepsy of temporal lobe origin (TLE).
Methods : Hippocampal, temporal lobe, and extratemporal lobe volumes were examined with 3–mm spin-echo coronal MRI scans in patients with unilateral TLE who were candidates for temporal lobe resection. Measures were adjusted for normal variation due to intracranial volume and age based on 72 healthy male controls. Group differences between 14 male TLE [7 left TLE (LTLE), 7 right TLE (RTLE)] patients and a subset of 49 age range-matched controls were examined with analysis of variance (ANOVA).
Results : As compared with controls, patients with TLE had smaller temporal lobe and frontoparietal region gray matter volumes, bilaterally, smaller temporal lobe white matter volumes bilaterally, and larger ventricular volumes. In contrast to these bilateral tissue volume deficits, hippocampal volume deficits in TLE were ipsilateral to the epileptogenic temporal lobe.
Conclusions : Extrahippocampal volume abnormalities were bilateral and occurred in both temporal and extra-temporal cortical regions in TLE, whereas hippocampal deficits were related to the side of the epileptogenic focus. These data suggest that brain abnormalities in TLE are not limited to the epileptogenic region.  相似文献
6.
Magnetic Resonance Imaging in Developmental Disorders of the Cerebral Cortex   总被引:12,自引:12,他引:3  
Ruben I. Kuzniecky 《Epilepsia》1994,35(S6):S44-S56
Summary: Developmental disorders of the neocortex are commonly associated with epilepsy. The development of magnetic resonance imaging (MRI) has advanced our understanding of these disorders by permitting accurate recognition and clinical correlation during life. These disorders have multiple etiologies and are dependent on the time of injury to the developing nervous system. MRI has permitted the classification of these malformations in three major groups: generalized disorders, unilateral hemispheric, and focal disorders. Generalized disorders include lissencephaly, pachygyria, band heterotopia, and subependymal heterotopias. Hemimegalencephaly comprised the unilateral disorder. Focal lesions include focal cortical dysplasia, polymicrogyria, schizencephaly, and focal subcortical heterotopias. The information provided by MRI, in conjunction with the clinicoelectrographic features, is extremely important in the recognition of these syndromes and for the appropriate medical and surgical management of those patients with epilepsy.  相似文献
7.
Summary: Twenty-two patients with intractable complex partial seizures (CPS) were treated with temporal lobectomy. Eighteen of 22 (82%) are seizure-free while receiving medication, with a mean follow-up time of 4 years. In each case, the clinical seizure pattern, interictal and ictal scalp EEG, magnetic resonance imaging (MRI), neuropsychological testing, and results of the intracarotid amobarbital procedure (IAP) converged to indicate a localized abnormality. None of the patients in this series had mass lesions, vascular malformations, or cortical scars, but 18 of 22 had hippocampal atrophy on MRI and 20 had hippocampal sclerosis (HS) on pathologic examination. We believe it is possible, on the basis of the preoperative evaluation described, to identify a population of epileptic patients who will do very well postoperatively. Such patients do not require invasive EEG monitoring, and they represent ∼20% of the patients treated surgically in our epilepsy unit in the past several years.  相似文献
8.
目的 研究抑郁症首次发作(以下简称首发)患者对不同性质情绪线索的差异脑激活反应,以探讨抑郁症患者"负性情绪偏向性"的脑活动特征.方法 14例抑郁症首发患者与14名配对健康对照者,接受国际情绪图片系统中正性-中性-负性三组图片刺激的脑功能磁共振成像(fMRI)扫描,任务为组块设计;以文拉法辛(75~150 mg/d,口服)治疗患者,随访12周;以汉密尔顿抑郁量表(HAMD17)减分率评估疗效;用神经功能影像分析(AFNI)软件处理影像数据.结果 (1)文拉法辛治疗8周时有效率为58%;12周时有效率为92%,HAMD17总分减分率为60%.(2)两组均激活的脑区包括双侧额中回、双侧背外侧前额叶皮质、左侧丘脑、双侧岛叶、双侧颞叶、双侧杏仁核和海马.(3)在正性/中性图片激活的脑区中,患者组双侧额中回(右侧0.11%,左侧0.09%)及左侧丘脑(0.31%)激活强度均低于对照组(分别为0.98%,1.17%和1.32%;P<0.05);左侧岛叶(1.03%)及双侧杏仁核(右侧0.47%,左侧0.11%)的激活强度高于对照组(分别为0.45%,-0.34%和-0.49%;P<0.05).对于负性图片,患者组左侧额中回(2.77%)、左背外侧前额叶皮质(0.18%)、左侧岛叶(1.36%)、左侧颞叶(0.33%)和右侧杏仁核(0.44%)的激活强度高于对照组(分别为1.91%.-0.32%.0.91%,-0.31%,-0.29%;P<0.05);患者组左侧丘脑激活强度(-0.79%)低于对照组(1.15%;P<0.05).(4)治疗后,对于正性图片,患者组左侧、右侧额中回及左侧丘脑激活增加为1.21%,1.14%及1.23%(P<0.05).对于负性图片,左侧额中回(2.05%)、左外侧前额叶皮质(-0.42%)及左侧岛叶(0.73%)的激活降低(P<0.05);左侧丘脑(1.53%)激活增加(P<0.05).结论 前额叶、左侧岛叶、左侧颞叶、杏仁核和左侧丘脑对不同性质情绪诱导线索的异常激活,与抑郁症首发患者偏向性情绪障碍相关;文拉法辛对前额叶、左侧岛叶和丘脑的异常激活有调节作用.  相似文献
9.
Summary: The mechanism of interictal glucose hypometabolism remains unclear, but this abnormality occurs more frequently in temporal lobe epilepsy (TLE) than in other types of partial epilepsy. Therefore temporal hypometabolism has been suggested to reflect mesial temporal sclerosis (MTS). To investigate this, we selected 22 patients with refractory partial epilepsy of mesial temporal lobe origin (MTLE) who had hippocampal atrophy based on magnetic resonance imaging (MRI) volumetric analysis. We then analyzed the metabolic correlates of unilateral hippocampal atrophy. Thirteen temporal regions of interest (ROI) were defined on MRI scans for each individual and then applied to high-resolution FDG-positron emission tomography (PET) images obtained parallel to the long axis of the hippocampus. The most hypometabolic regions were the temporal pole and the hippocampal region. When we analyzed ensembles of temporal regions grouped into related networks, the temporolimbic network, which included the hippocampal region and the temporal pole, was abnormal in 95% of the patients at a 3-SD threshold. PET hypometabolism was highly correlated with the degree of hippocampal atrophy in this network, but not in other parts of the temporal lobe, which were less frequently hypometabolic. These data indicate that hypometabolism is a consequence of MTS in the temporolimbic region but not necessarily in the other parts of the temporal lobe. Our results also suggest that the combination of PET and MRI may facilitate the noninvasive diagnosis of MTLE.  相似文献
10.
Summary: Purpose : We measured absolute volumes and volume differences of hippocampi in patients with mesial temporal lobe epilepsy (MTLE) using volumetric magnetic resonance imaging (MRI) to determine the extent of bilateral atrophy in MTLE and to relate hippocampal volumes (HV) to outcome of temporal lobectomy.
Methods : HV and hippocampal differences (HD) were measured in 40 patients with MTLE determined by pathology of hippocampal sclerosis (HS) and compared with those of age-matched controls. Results were matched with surgical outcome.
Results : Hippocampi contralateral to lobectomy (right hippocampi 2.96 ± 0.49 cm3, left 3.14 ± 0.51 cm3) were significantly smaller than those of controls (right hippocampi 3.73 ± 0.52 cm3, left 3.60 ± 0.51 cm3 but were significantly larger than hippocampi ipsilateral to lobectomy (right hippocampi 2.63 ± 0.61 cm3, 2.18 cm3) as compared across groups by analysis of variance (ANOVA: F = 27.2, p < 0. 0001). The smaller hippocampus was ipsilatera1 to lobectomy in 39 of 40 cases. Seven of 40 MTLE patients (18%) had bilateral atrophy, defined by volumes of each hippocampi 2 SD lower than control means. Surgical outcome was independent of hippocampal asymmetry and bilateral atrophy measured by chi-square and Fisher's exact tests.
Conclusions : We determined that most patients with MTLE have some degree of bilateral, asymmetric hippocampal pathology. However, asymmetry and bilateral atrophy have no clear relation to surgical outcome.  相似文献
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号